The prior art cooking vessel is described in U.S. Pat. No. 4,700,689, issued Oct. 20, 1987. Related patents include U.S. Pat. Nos.:
1,202,216, issued Oct. 24, 1916; PA1 2,002,237 issued May 21, 1935; and, PA1 4,590,919, issued May 27, 1986.
The prior art cooking vessel includes a pan and a cover, which has a fixed inner diameter.
One problem with the prior art cooking vessel is that the cover is not adjustable in diameter, so that the cover does not fit some pans of larger diameter or smaller diameter. Another problem is that the height of the enclosed cooking chamber is not adjustable for a given diameter cover.